Sonic-Frozen Crossover
by firewaterwarriorKats
Summary: What the title says. Once upon a time, two royal sisters of Arendelle were separated at a young age by a secret-and a promise. On the older sister's coronation day, her fiery secret is revealed and the kingdom is in danger. Only the younger sister and her companions can save the day, but why does the new queen have these powers? And what does that have to do with the legend of Sol?
1. Chapter 1

Sonic-Frozen Crossover-Prologue

 **Hello, firewaterwarriorKats here. This isn't my very first fanfiction (my very first was terrible, with an inconsistent plot, so it's happily retired), but this is my first story here on the site. I have posted this story before on Deviantart, but I had to close my account due to personal reasons, so don't try looking for the rest of this story there. Note that this is unfinished and currently on hiatus, so if I don't update this story after chapter 7, you know why.**

 **Anyway, I was pretty stoked for this story when I first started it back in 2015, and even now, this is one of my more lighthearted stories on file. I will be uploading one or two chapters per week, depending on work and school and your guys' requests for more. So, read on and if you like it, please by all means review and comment. If you see something that needs improving, then by all means, review and tell me where! I would love to improve my writing anyway I can, so informing me about choppy or confusing parts of the story and how I can improve will help you and me a lot.**

 **Anyway, enough of my babbling. Enjoy!**

In a place where kingdoms reign and tales are timeless, in a northern kingdom there were two sisters. One was a purple cat and the other was a pink hedgehog. Though not seeming to be sisters, they were, and when they were young they would often be seen playing together like best buddies.

Until one day one of them decided to stay apart from everyone else. The older sister locked herself away from society and shut people out of her life. She stayed in her own self-isolation, listening to her younger sister from outside her bedroom door and wishing things didn't have to be this way.

But it had to, she would always remind herself. She kept hidden a secret, one she didn't want anyone else to know, not even her own sister. She wanted everyone to be safe, and she knew if that were to be accomplished, she would have to stay away from other people. So strong was her secret and desire to protect that she stayed in her isolation for years, always trying to control her secret and wishing for things to be different.

On the other side of the door, the younger sister wandered throughout their palace (for they were daughters of royalty), wanting for some company. Her older sister's isolation affected every aspect of palace life, and often she would ask her silent sister to come out and end the loneliness. This didn't happen, however, and the younger sister longed for a life without boundaries and filled with happiness and freedom. But most of all, she longed for company, and to have her sister back.

For years, this story played over and over again, neither sister giving way from their positions in this lonesome place. Life went on, and both became grown and ready for change.

Finally the day came, and on this special day our story truly begins.

Coronation Day is here.

 **So, how was it? Good? Needs improving? Let me know!**


	2. Chapter 2

Sonic-Frozen Crossover-Chap.1

It was Coronation Day, and everywhere in the kingdom of Arendelle everyone was in a bright mood. Banners bearing the emblem of the kingdom were hung up on every street lamp, and children were seen weaving their way between the grown-ups busy getting ready for the upcoming coronation of their new queen.

One such pair, a blue hedgehog and a younger two-tailed fox, stood together next to a sled full of huge chunks of ice. They both called out to the people bustling to and fro in front of them, trying to convince them to buy some ice. Unfortunately for them, sales for the day were very unproductive and all they got from their efforts were pennies, literally.

The hedgehog bent down to pick up the mere change lying at their feet.

"I hate selling ice!" he complained. "This is the lamest job in the world!"

"But it's our only way to get by," the fox consoled. "How would you like it if we took up that job offer, shoveling out horse poop every day?"

"At least we would've gotten a solid pay!"

"But seriously, you would take up that job if it were available and end up getting even smellier than you are now?!"

"I would if I could, Tails," the hedgehog placed the change in his pocket and leaned against the ice on the sled. "But this is the only job available now. And no one else was willing to go up the Northern Mountain for ice except you and me. I just wish things would be different."

"Don't worry, Sonic," Tails placed a hand on his companion's shoulder. "Maybe our new queen will set up more jobs for nearly unemployed people like us to take up."

"Hopefully," the hedgehog said wistfully as he looked towards the castle.

Meanwhile, one very excited pink hedgehog princess was hopping from room to room, taking in the new look of her home with all the windows open and pouring in the sunshine.

"Who knew people did that anymore?!" she asked herself as she entered a room filled with paintings of people. Flopping down on one of the couches, she began to conversate with them.

"I mean, seriously, who knew we owned 8,000 salad plates? This is so exciting, I don't know if I'm elated or gassy! People are coming; I just can't wait to meet everyone."

Suddenly she gasped out loud. "What if I meet **the one**? Just imagine, tonight will be a ball and I'll be all dressed up for the occasion, looking so pretty everyone will be jealous, and all of a sudden, Boom!, there he is, a tall and fair stranger, and oh my gosh, will he be handsome! Ahh, I'll just want to stuff some chocolate in my face! Ohh, and we're gonna laugh and talk all evening, which is totally bizarre, I'll admit, but it will be completely different from the life I've led so far!

"You guys are so right! For the first time if forever, there's going to be fun and magic and light! For the first time in forever, who knows, I could be noticed by someone! Yeah, I know it's totally crazy, dreaming about romance and stuff like that, but for the first time in forever, at least I got a chance."

Inside a single isolated room, a purple cat paced the room nervously, anxious for the trials ahead. Her coronation was only a few hours away, and even now she could imagine all the things that could go wrong today.

Anxiety pricked at her fur as she reminded herself of the lessons she taught herself during her isolation. Absentmindedly, she picked up a metal oval-shaped box and the candlewick that were lying on her desk.

"Conceal your powers. Don't feel. Don't let them in, don't let them see. Be the good girl you always have to be. Put on a show…Make one wrong move and everyone will know…"

She looked down. She inhaled sharply and quickly put down the smoldering remains of the box and candlewick. They had been heated up to such a degree that they had begun to melt in her hands.

Berating herself for not controlling her powers, the cat stepped away from the desk, tugging on a pair of gloves over her hands, and looked out the window. She could see the decorations her people had set up in celebration for her upcoming coronation. Allowing a small, sad smile to play at her features, she stepped away from the window.

"It's only for today, Blaze," she consoled herself. "Just for today. Then everything can go back to the way it was. Oh, it's agony to wait. Let's get this over with."

For the first time since the beginning of her isolation, Blaze went to the door of her room, twisted the handle, and opened the door.

"Tell the guards to open up the gates!" she ordered the guard down the hall. The guard saluted and went to accomplish the task. Blaze stayed at the doorway for a moment, wondering what her sister could be doing at this time.

 **Yay, first chapter came early! Just so you know, these chapters were already written about 1-2 years ago, so it's ok if something is a little wacky, just plz let me know where I can improve in the reviews or PM.**

 **Anyway, I really loved writing Sonic and Tails in this story. Their brotherly relationship was tons fun to work on! ^^**

 **Hope you like the story! Plz R & R!**


	3. Chapter 3

Sonic-Frozen Crossover-Chap.2

The pink hedgehog gasped out loud as she heard her sister's voice for the first time in forever, hearing her order for the gates to be opened. For a moment, her heart fluttered inside her chest in excitement.

"It's time!" she almost squealed. "Oh, if only it was only for today! It's agony to wait! I just gotta go out!"

Jumping off from the couch, she raced down the hallway and out into the castle courtyard. She hopped up and down, barely containing her excitement, and gazed in wonder as the gates were opened and people began to enter the castle walls.

"This is amazing!" she whispered to herself, and skipping along she made her way through the crowd to explore the town.

She gazed at the decorations with a gleam in her eye. All the people crowding around, waiting to get into the castle, were very nice and happy to see her. Just as she thought there was nothing to stand in her way now, she tripped and fell into a small rowboat. The boat started to tip over, right into the water below. Before the hedgehog could stop it, something else leveled out the boat for her.

She looked up. A proud light tan horse stood there, with one foot planted firmly onto the boat. Riding it was a handsome black hedgehog with gray stripes and lime green eyes, and he bore a certain nobility in the way he sat proudly and yet so kindly on his horse. He reached out a hand.

"Need some help there?" he asked with a gleam in his eyes.

For a moment the princess was speechless, caught in the moment.

The handsome noble stepped down from his steed and bowed low to her. "Princess Amy," he said with dignity.

His horse made to bow, too, but with the pressure eased the boat began to tip over again. The handsome hedgehog fell over Amy as the boat tipped precariously over the edge. The horse noticed their plight and stomped hard on his corner of the boat, abruptly leveling out the boat and tipping both hedgehogs on the floor of the little boat, with Amy on top of the handsome hedgehog.

"This is awkward," Amy said nervously, words rushing through her mouth. "Not that you're awkward… it's just…we're…I'm awkward. You're gorgeous. Wait…what?"

The handsome hedgehog gave a small smile at hearing her awkwardness. "It's alright," he said. "By the way, I'm Prince Shadow of the Southern Isles. But, please call me Shadow."

"Shadow," Amy whispered the name with a wistfulness that came from crushing on someone.

Suddenly she heard the bells toll, the signal that her sister's coronation was beginning very soon. Reluctantly, she pulled away from Shadow and stepped out of the boat.

"I'm sorry," she said. "But the coronation is going to start soon. I need to get going."

"Don't worry, Amy," Shadow replied. "I was invited to the ball tonight. We'll talk later."

"Okay," Amy said, walking away. "See you later."

Shadow and his horse watched the pink hedgehog go, both inattentive to what was going on. The horse had let go of the boat, and he noticed too late that his rider was still in it. The horse turned his head just as the boat fell into the water.

 **Okay, before anyone says anything, this isn't exactly my best chapter, its mainly just set up for more of the story. And yes, Shadow's description is correct. I'm fairly certain some of you readers know where this is going...**

 **Anyway, R & R!**


	4. Chapter 4

Sonic-Frozen Crossover-Chap.4

As night began to fall, Sonic and Tails watched the castle windows as nobles from all around cast shadows against the light pouring out from them, dancing to some light and happy tune in that grand ballroom of theirs.

Sonic turned away and started to hook himself to the sled.

"Let's get going', little bro," he said.

"Huh?" Tails turned around. "We're leaving already?"

"Yes," Sonic grunted as he began to push the sled. "No one's going to buy ice today around here. We should go up to that one place with the inn, maybe those guys'll want some ice."

Sonic began to pick up speed, throwing his weight against the wind as its summer coolness gently nipped at his nose.

Tails cast one last glance at the palace, then he shrugged it away as he followed his childhood brother into the wilderness.

Amy watched the dancers in the ballroom at a respectable distance. She smiled as she watched their graceful movements, seeming to glide across the room. Her sister stood on the steps of a raised platform, watching it all with a noble neutrality that slightly irritated Amy on the inside.

'Why does she have to be like that all the time?' she asked herself. 'She never lets anyone get close to her…not even me.'

One of the castle stewards came up to her. "You must presume your place next to your sister."

"Wait, what?" Amy was caught off-guard, but could complain no further as he gently took her arm and led her next to her sister.

They stood in awkward silence together for a few minutes, the years of silence defining their relationship.

"Hi there," Blaze said.

"What? Oh, hi there. Yeah, hi." Amy could still feel the awkwardness between them.

"You look nice tonight."

"Thank you. So do you."

"Thanks."

Their conversation was broken by one very round nobleman whose brown mustache bristled outward from his face.

"My lady queen," he greeted in an eloquent manner. "As the Duke of Egglton (pronounced Eagleton, mind you), which is currently your most loyal trading partner, it will be my honor to lead you into your first waltz as Queen?"

"No thank you," Blaze kindly replied. "I don't care much for dancing."

"Princess," the nobleman took Amy's hand in his own. "Would you care to dance with me in your sister's place instead?"

"Uhh," Amy desperately looked to her sister for help. "I don't really- whoop!"

Before she could reject the offer, the older gentleman pulled her onto the dance floor. He began to dance in a way that was awkward and would've embarrassed Amy if she had tried to dance like that. Standing stiffly while the gentleman tried in vain to impress her with his dancing skills, Amy looked to her older sister. Blaze was giggling at the scene.

Once she had the opportunity, Amy managed to get away from the gentleman.

"He can work up a storm, dancing with those gangly limbs. And he's wearing heels!"

"Goodness," Blaze replied.

"This has been so much fun," Amy breathed. "I wish it could be like this all the time."

"I do too," Blaze said before she could check herself. But remembering her duty to keep her secret, she added sadly, "But it…just can't be."

She turned away and immersed herself in the crowd. Amy wondered what that meant, and before she could go after her sister, she spied smoky black and grey quills bristling smoothly out from a handsome hedgehog's brow.

Smiling to herself, she pursued the handsome Shadow.

That night was perhaps one of the best in Amy's entire life. She had a terrific time with Shadow, who confessed that there may be something going on between her and himself. She realized that he was probably the most ideal person she could ever get hooked up to, and even more so since he basically had rights to his kingdom taken up by a multitude of brothers.

"Twelve, to be exact," he had said. "And I'm the youngest out of all of them."

Amy didn't mind, though. She really liked this seeming-perfect guy, and he seemed to like her. They spent the night just as she envisioned it, laughing and talking with her Prince Charming.

In the middle of their discussion, Shadow took Amy's hand in his.

"Can I say something crazy?" he asked. Amy giggled, motioning for him to continue. "Will you marry me?!" he asked almost pleadingly.

"Can I say something even crazier?" Amy asked. "Yes!"

 **Now presenting, the Duke of Egglton-**

 **Eggman: Eagleton! Eagleton, get it right, author!**

 **Ahem! The author can pronounce it however she wants!**

 **Anyway, coming up with these alternate characters was fun, especially the Duke. There was so much potential for Eggman as the Duke, and I really hope I pulled him off. If these two met, I guarantee they would hit it off very well.**

 **R & R!**


	5. Chapter 5

**Hey, two chapters in one day! Horray!**

 **Hello again, and thanks to all who have read this story so far! Your support for this story makes me more and more excited to share this tale with you, so thank you very much!**

 **So, this chapter finally gets the plot moving, and I believe we all know what's about to happen. Enjoy!**

Sonic-Frozen Crossover Chap.5

Amy led Shadow by the hand, guiding hem through the crowd to meet her sister. Near the center of the ballroom, she spotted Blaze wrapping up a conversation with some other nobles.

"Wait a minute," Shadow paused, stopping so that Amy could hear what he had to say. "I forgot to mention it, but how did you get that?" He pointed to a small streak of purple going down the length of one of her spines. The streak was the same shade as the rest of Amy's spines, and it suggested a kinship with Blaze.

"Oh," Amy fingered the mark. "I was born with it. But I dreamed I got kissed by a Chao!"

Shadow chuckled. "You're so funny! Let's talk to your sister now, and see if we can get her blessing."

"Oh, right," Amy giggled apologetically.

Once the twosome had weaved their way past the throng of nobles, Blaze looked up to see them coming.

"Hi! It's me again," Amy said. "Blaze, I would like to introduce Prince Shadow of the Southern Isles."

"A pleasure to meet you, Your Highness," Shadow bowed.

"Same here," Blaze returned the gesture. She cast a questioning glance at Amy. 'Why did you bring him?' she seemed to ask.

"Umm, Blaze, we want…"

"…Your blessing," Shadow filled in for her. They giggled a bit, and then they blurted out, "For our marriage!"

Blaze looked like she had been hit by a bus. Her surprise was obvious, but what wasn't so obvious was the storm within that was stirring inside of her. "Marriage?" she echoed in disbelief.

The two nodded with smiles on their faces. It was maddening. "I'm sorry, I'm confused."

"Well, we haven't gone over the details ourselves," Amy explained. "We'll have to plan the invitations, the ceremony, honeymoon, the ice cream-oh," she paused, turning suddenly to Shadow. "Can you move here?"

"Here?" Blaze asked, but her question was overlaid by Shadow's response of "Absolutely!"

"We can invite all twelve of your brothers to stay here!" Amy continued.

"Whoa, wait, slow down," Blaze cut in. Deep inside, she could feel the beginnings of her storm getting stronger. She quickly tried to take control of the situation.

"No one's brothers are staying here, no one's getting married."

Amy's excited expression flattered into one of disbelief. "What?"

"Amy, can I talk to you, please," Blaze asked. Taking a single quick glance at Shadow, she added, "Alone?"

"No," Amy replied, clinging to Shadow's arm. "Whatever you have to say, you can say to the both of us."

"Very well," Blaze concluded. "You cannot marry someone you've just met."

"But you can if it's true love," Amy argued.

"Amy, what do you know about true love?"

"Well, more than you. All you know is how to shut people out."

Blaze seemed to be taken aback for a moment, realizing the truth in Amy's statement. It was true that Blaze shut everyone out of her life, for nearly her entire life. But she had a very good reason for that, and that reason was the storm that was building up inside. They would never, could never, understand her actions.

Blaze recovered in an instant. "You asked for my blessing, but my answer is no," she asserted. "Now, if you'll excuse me."

As she began to walk away, Shadow tried to resolve the situation. "Your Highness," he began to say. "If you may permit me to speak-"

"No, you may not," Blaze interrupted before he could make his suggestion. "I think it's time for you go to." The lilac cat turned to one of the guards. "Close the gates," she ordered. "The party is over."

Amy reached over to her sister. "No wait, please." She had meant to grab her arm, but she missed and instead she took her glove.

Blaze realized what happened instantly. She gasped and recoiled, hiding her exposed hand in the cloak. "Amy, give me back my glove!" she demanded.

"No, Blaze, please I can't live like this anymore!" Amy cried.

"Then leave," Blaze said. It broke her heart to have to say those words to her sister, but it was all for her safety and everyone else's. With a sad expression, Blaze turned away and tried to walk out.

"What did I ever do to you?!" Amy cried after her. All around the room, people turned and watched the exchange.

"Not now, Amy," Blaze said through clenched teeth. The storm within was growing, crackling and spitting out of control inside of her. She could feel it as strongly as the fear that was rising like bile in her throat as Amy continued to push.

"Why? Why do you shut me out? Why do you shut the world out? WHAT ARE YOU SO AFRAID OF?!"

"Amy, I said enough!" Blaze turned in order to prove her point, and instinctively she used her exposed hand to move her cloak out of the way.

Fire erupted from her hand, and the floor melted into a mass of jagged edges from the heat of the flames. The mass had Blaze entrapped in a ring of heat, all alone within the flames.

Everyone gasped in shock, as the intense heat and the realization of what had just happened began to sink in.

The Duke who had led Amy into the embarrassing dance before pecked around from behind his two robot bodyguards. "Sorcery," he hissed, glaring at the new queen. "I knew there was something devious going on here."

Blaze looked at the people in the ballroom in fear. The one thing she had hoped would never happen just did: her curse was exposed.

"Blaze?!" Amy called out, but the only thing that seemed to respond was the swinging door and the end of Blaze's cape as she tried to escape the scene, her fear-and herself.

 **R & R!**


	6. Chapter 6

**Hello, sorry for the late update. Yesterday was a pretty busy day, and I wasn't able to access my computer due t a number of reasons which I won't bore you with now. What you do need to know, however, is my work school life balance is a little shaky so updates will be spontaneous at best. For those who are reading my other story, Project: Chaos Control, I will be posting a chapter before Friday, but after that I will be on vacation and there will be NO WIFI! So, yeah, if you post a review, I may not reply till around Monday because of this.**

 **If you want to hear more, then be on the lookout for Project: Chaos Control this week. Until then, enjoy!**

Sonic-Frozen Crossover Chap.6

Sonic and Tails were dashing through the forest, heading toward their intended destination, when Tails called for a quick stop.

"Hey Sonic," the two-tailed fox leaned over the sled, checking the ice. "Is it me, or has the temperature gone up?"

Sonic skidded to a stop, remembering something. "Shoot! I didn't put the coverings over the ice when we got to Arendelle!"

"Well, thanks for the information," Tails said in a sarcastic tone, glancing back over the sled. "All the ice had melted."

"Darn! Now we gotta go to the North Mountain and replenish our supply!"

"Wow, it got hot all of a sudden, don't you think Sonic?" Tails wiped his forehead in a gesture that said he was heating up.

Sonic whistled as a warm breeze stirred the air around them. "You're right, little bro. Let's get to the North Mountain, before this heat melts the rest of our ice!"

Tails nodded approval as Sonic started running again, racing against the heat that had started to rise.

...

Blaze burst through the front doors to the palace, only to gaze upon the crowd of Arendelle citizens that had come to celebrate her Coronation.

'Great,' she thought, hesitating to go onward. 'A big crowd full of people is just what I need right now.' However, hearing the pursuing footsteps of the ballroom guests, she was forced into the crowd.

It was all a maze of faces and bodies as Blaze tried to push her way past the people. At one point, a man bowed to her, and she couldn't see a way around.

"Queen Blaze," the man greeted her. In the next second, the panicking queen found an opening. She shoved her way through, and was once again forced to stop as the crowd became too thick to push through.

An older woman carrying a baby looked at her curiously. "My lady," she inquired gently. "Are you alright?" The baby laughed at the sight of the new queen.

"No," Blaze whispered to herself, backing up fearfully. Just behind her, a fountain poured water in a grand display. Blaze bumped into it and nearly lost her balance. She grabbed the edge of the fountain's pool to keep from falling in.

Fire and intense heat touched the stone from where Blaze's exposed hand touched the fountain, spreading into the water and upward, engulfing the water and instead making the fountain shoot liquid flames into the sky.

The crowd stepped back from the suddenly burning fountain, stunned at the intense heat and the way the flames licked the stone and hungered for something more to consume.

Blaze backed off, panic rising. Just then, the Duke and his robot bodyguards erupted from the palace doors, calling for someone to stop the queen.

"No," Blaze called, trying in vain to keep down the panic that was boiling inside of her. "Just…stay away from me. Stay away!"

As she said the last few words, a fireball erupted from Blaze's hand against her will, exploding with a loud bang on the steps leading up to the palace and reducing them to melted stone.

The duke and his robots were sent flying, blown away by the impact of the blast. The Duke recovered first, pointing at the feline queen and crying out, "Monster! Monster!"

The citizens cowered before the queen everywhere Blaze turned. Over and over again, she saw her worst nightmares being relived as the woman from before held her child close to her and away from the queen, and the men bringing children close to their bodies and backing away from her.

Blaze could not stand this. She knew now that she could no longer hide her powers, and these people would probably set out to destroy her in order to keep themselves and their loved ones safe. She knew what she had to do.

After only a moment's hesitation, she ran.

Amy got to the doors at that moment with Shadow at her heels. She quickly took in the melted steps and the flaming fountain, but she had her sights fixed on her escaping sister.

"Blaze!" she cried, skirting past the melted steps and jumping down onto the courtyard, in hot pursuit of her sister. Shadow followed, glancing at the Duke before taking off after his love.

Blaze ran until she reached the edge of the fjord, with no solid ground to run on. She was trapped.

"Blaze!" Amy called over the wall. Blaze backed away from the palace, cornered and afraid. Flames sprouted under her feet as she backed up towards the water, getting so intense that for a second the queen was hovering over the ground.

Surprised, Blaze turned around. The flames had scorched the ground underfoot, and they had stopped at the water. They reached upward instead, hungrily licking for more to consume. That, and her momentary levitation, gave the queen another route of escape.

Amy burst through the gate leading to the edge of the water, finally catching sight of her sister. "Blaze!" she called out, practically begging her to stop.

Blaze glanced at her once, and then she stepped out onto the water.

Just as she had hoped, the flames under her feet surged upward to get away from the water, allowing Blaze to fly over the fjord. Without a glance back, Blaze put on a burst of speed and left Arendelle behind.

"Blaze, stop!" Amy cried out pitifully, tripping over the burnt ground and nearly splashing into the water. Shadow caught her just in time, and they watched hopelessly as the flaming queen blazed away in a flaming comet. Amy still held her sister's glove in her hand, and she clutched it like a dear toy.

Shadow turned as a peculiar glow emanated forth from the highest tower of the castle. Deep inside, seven beautiful, rectangular-shaped emeralds in various colors sensed what had happened, and their power shone forth to right the wrong that had befallen the kingdom.

Shadow turned back, and froze in shock.

"Amy," he said, getting her attention. "Look at the fjord." The pink hedgehog did, and gasped out loud.

The entire body of water was freezing over, stranding ships in the middle of the fjord and trapping everyone in Arendelle. Clouds covered the night sky, and they released a light snow shower.

Shadow and Amy made their way back to the courtyard, amid the confused and surprised crowd of guests as they took in this new development of winter weather in the middle of summer.

Shadow put a hand on Amy's shoulder. "Are you alright?" he asked worried.

"No," she replied, almost incredulously.

"Did you know?"

Amy looked at her fiancé. "No."

 **Things just got a bit interesting, didn't it? I think I mentioned once before that the plot of this story will deviate a little bit from the movie just so it's not just a rehashing of what we already know. After all, this is a Sonic crossover, is it not?**

 **Anyway, hope you liked it. R & R!**


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